Pivoted bender with reversible clamp and former



Nov. 30, 1948.

G. c. H. PERKINS 2,455,138 PIVOTED BENDER WITH REVERSIBLE CLAMP AND FORMER Filed Aug. 1e, 194e 2 Sheets-Sheet l lNov. 30, 1948. G. c. H. PERKINS 2,455,38

PIVOTED BENDER WITH REVERSIBLE CLAMP AND FORMER Filed Aug. 16, 1946 2 Sheets-Sheet 2 I I l I I I I I I I I I I' Patented Nov. 30, 1948 UNiTED STATES PATENToFFIcE PIVOTED BENDER WITH REVERSIBLE CLAMP AND` FORMER Y George C. H. Perkins, Hamilton, Mass. Application August 16, 1946, Serial No. 691,096

6 Claims. 1

This invention consists in an improved machine for bending pipes, tubes or rods, and has the general advantages of simplicity and ruggedness in structure combined with low cost of manufacture and a wide range of capacity.

Tube bending machines now available are either are so light and unreliable that they have a short effective life and are a constant annoyance to the user on account of bent pivot or retaining pins are obviated and certain other important advanand the clamping face of the holding bar. This construction permits convenient interchange of die bending blocks and holding 'bars so that the machine may be easily adapted for a wide range of sizes.

Preferably and as herein shown, my machine is so organized that the bending operation may be reversibly carried out, that is to say, the movable clamping member may be swung either clockwise or counter-clockwise thus adapting the machine for forming either right and left-hand bends as may be required by the particular work in hand.

These and other features of the invention will.

owing description of a preferred embodiment hereof, selected for purposes of illustration an hown in the accompanying drawings in which:

Fig. l is a plan view of the machine showing a ube clamped preparatory to bending,

Fig. 2 is a corresponding view in elevation,

I0 is straight and the anged guide I I is located a short distance within this straight edge. The other edge of the base plate is curved on a radius struck from the axis of the pivot pin I2. I

The parts of the machine which are stationary in the bending operation include a clamping member comprising a bar I3 of rectangular sec# tion having at its inner end a at eye I4 offset upwardly above the lower faceof the bar and per'l foi-ated to receive the .pivot Fig. 2, the bar I3 is provided pin I2. As shown'fin at its outer end with shown in Fig. 3, or a right-hand bend in a manner to be presently explained.

The ear I5 is drilled and threaded to receivel a `clamping screw I9 which bears at its inner end against a long angular carriage 20. As shown in Fig. 2, the carriage is provided iianged tongues 2| and 22 which project downwardly from its lower face. As shown in Fig. 2, the tongue 2| engages the ilanged guide II and is inoperative, but if the position tongue 22 becomes operative. In the carriage 2i) is removably placed a long holding bar 23 and this may be grooved or recessed in its four faces to accommodate tubes of `diierent diameters; for shown in Fig. 4 its inner face has tube of larger diameter.

The swinging clamp shown by itself in Fig. 5 includes a-bar head 26 so located that the flat eye I4 of the stationary clamp'will fit beneath it. The head 126 25 having atits inner end a flat 3 is extended transversely as shown in Figs. l and 3 and is provided centrally with an upstanding retaining pin 21. Both ends of the head are periorated to receive the pivot pin I2. One of these perforations 28 is shown in Fig 3, and the other is filled by the pivot pin I2. At its outer end the bar has an upstanding ear 29 and a cylindrical handle 30 by which the clamp may be swung about the axis ofthe pivot pin I2 either directly or with the'assistance of a length of pipe which may be slipped over the handle 30. The upstanding ear 29 is drilled and threaded to receive a clamping screw 3i and this is connected at its inner end to a short carriage 32 corresponding in outline to the long carriage 20. In the carriage 32 is placed a short holding barI 33 which is provided with recesses corresponding to those of the long holding bar 23.

A die bending block or former 35 is removably held by the stationary pivot pin I2 and the movable retaining pin 21 and for this purpose. is provided with parallel vertical holes spaced to accommodatethese pins. 4As shown in Fig. 4, the edge faces o the die 35 are recessed to correspond to the recesses of the longholding bar 23 and the short holding bar- 33, having recesses 36. The inner end of thedie` block is semicircular and concentric with the pivot pin I2, while its side edges extend as parallel tangente to `its curved end. f

The operation ofthe machine lwill be apparent from the foregoing description but may be summarized as follows. l Having equipped the machine with a long holding bar 23, a short holding bar 33, and a bending die 35 suitably recessed to fit the tube or rod` which it is desired to bend, the clamping screws I9 and 3 I are both retracted and the movable clamping member is moved into parallelism with the stationary clamping member as shown in Figs. 1 and 2.y A

the die block, as suggested in Fig. 1. The clamping screw 3I is then set up sufficiently to clamp the tube firmly against the straight wall of the bending die and the clamping screwv I9 set up suiciently to hold the tube frictionally but permit it to travel inwardly in the bending operation. The movable clamp is then swung about the axis ofthe pivot pin I2, as suggested in Fig. 3, to an index mark on the curved edge of the base plate i9 corresponding tothe angle of bend required. In the bending operation the tube is bent about the circular contour vof the bending die 35. When the desired .bend has been formed, both clamping screws may. bereleased and the bent tube removed lfrom the machine.

In Fig. 6 is shown a bending die 40 which is interchangeable with the bending die 35 and differs from it only in that its peripheral wall is provided with a single recess or groove of large diameter as compared to' the recesses or grooves 36 of the bending die 35. The die 49, like the die 35, is provided with a hole 31 to receive the pivot pin I2 and ahole 38 to receive the retaining pin 21, fl

When it is desir d to? .organize the machine for forming a right-hand bend, both the movable and stationary clamping. members are lifted oi the pivot pin I2 and replaced in similar but reversed positions on the other` side ,of the" base plate I0. The carriage 20 is also removed from the position shown in Fig. 1, turned end for` end, and replaced in reversed position ron the other side yof `the pivot pin I2.

The holding .bars andiirare helfen Shawn. as-` n tube 42 is then inserted lengthwise between the holding bars and having a single recess in one face and two recesses in the opposite face, thus adapting the machine for operating on three sizes of tubes. It will be apparent that these bars may have additional recesses of different sizes in their other two faces and thus adapt the machine for operation on tubes of various sizes.

The construction of the machine is such that the upright pins I2 and 21 have a oating relationship with their associated parts since the holes in which they are recessed are formed with substantial clearance. This feature is desirable as it greatly facilitates the removal and interchange of the bending dies. In bending machines as heretofore constructed a slight distortion of the holding pins has caused much diiculty in removing the dies. This difculty is overcome in the present machine by the floating connection of the pins and the fact that the bending die itself is used as the bearing housing.

Having thus disclosed my invention and described .in detail an illustrative embodiment thereof, I claim asnew and desire to secure by Letters Patent:

l. A tubebending machine comprising abase plate having a semi-circular edge andan upstanding pivot pin located at the center of its edge curvature, a projecting stop at each end oi said semi-circular edge, a stationary clamping member perforated to rit the pivot pin and to be engaged Withone or the other of said stops accordingly as the machine is organized for right hand or left hand bending, and a movableclamping member having transversely spaced holes in its inner end either. oi which may be fitted on said pivot pin.

2. A tube bending .machine comprising a base plate having Ian upstanding pivot pin, .abending die mounted to swing on said pivot, tube guiding means leading to the die, means for connecting the said tube guiding means to the said base on either sideof the said pivot pin for the purpose o right or left hand bending, and a swinging clamping member having a T-shaped head provided with an upstanding retaining pin for the bending die and being perforated to receive the said pivot pin at either end of the T-shaped head.

3. A tube bending machine comprising a base plate having a fixed upstanding pivot pin, a stationary clamping member perforated at its inner end to receive the pivot pin, means for securing the said stationary clamping member to the said base plate in veither of two positions.

180" apart with respect to the axis of said pivot pin, a movable clamping member having transversehr spaced holesin its inner end either of which may be fitted on said pivot pin and having an opstanding retaining pin, and a bending die having transversely spaced holes receiving the pivot pin and the retaining pin ofthe movable clamp-ing member.

4. A tubebending machine comprising abase plate carrying an upstanding pivot pin and a anged guide, a stationary clamping member held at its inner end by said pivot pin, separate means for. securing the said stationary clamping member to the said baseplate in a position parallel to the said hanged guide at either side of the said pivot pin, an'elongated carriage supported at itsouterfend on the said guide anc at its inner end supported on the said stationair: clamping member, an elongated recessed holdin; bar mounted in said carriage, a moveable clamp ing member having a head with transversel;

spaced holes either of which may ybe fitted on the said pivot pin and having an upstanding retaining pin, a bending die block perforated to receive both the pivot pin and the said retaining pin whether the movable clamping members is fitted to the pivot pin -by one or the other of its transversely spaced holes.

5. A tube bending machine comprising a base plate, a pivot pin located lcentrally in the b-ase plate, a stationary clamping member perforated at one end to t the pivot pin, means at the other end of the stationary clamping member for securing it to the base plate in either of two positions 180 apart with respect to the axis of said pivot pin, a movable clamping member having transversely spaced holes in its inner end either of which may be fitted on the said pivot pin, a straight line flange connected to the said base plate and disposed in parallel relation to the stationary clamping member, a carriage disposed at right angles between the flange and station- REFERENCES CITED The following references are of le ofk this patent:

UNITED STATES PATENTS record in the Number Name Date 165,804 Devine July 20, 1375 847,094 Monnet Mar. 12, 1907 1,650,955 Miller Nov. 29, 1927 1,919,839 Hilgers July 25, 1933 2,306,221 Parker Dec. 22, 1942 2,382,745 Powers Aug. 14, 1945 

